Update: The LG G4 has entered the Top 10 fray. Where has it ranked among the best phones? Read on to find out!

Knowing the best smartphone you can buy right now is more than just a hunch for us. We test out the latest and - sometimes - greatest phones in comprehensive mobile phone reviews.

To drill down to a list of our 10 favorites in the US leading into the second half of 2015, we based the updated rankings on a lot of geeked-out factors: design, performance, battery life and camera quality.

Sure, your personal preference among iOS, Android and Windows Phone could sway you to another device besides our top-ranked phone. Likewise, availability via AT&T, Verizon, Sprint and T-Mobile is an outlier. The best phone for AT&T may not be available on-contract on Verizon, and vice-versa.

But that's why we have more than just a No. 1 pick, which, spoiler alert, isn't Apple's iPhone 6 or iPhone 6 Plus. We're not that predictable. Before you lock into a binding contract or spring for an expensive unlocked, SIM-free smartphone, consult our best phone guide, updated regularly.

10. Nexus 6

The biggest smartphone on the list is the Nexus 6 from Google and Motorola. At a whopping 6 inches, it has room to compete with other flagships: a Snapdragon 805 processor, 3GB of RAM, all-day battery life, QuickCharge 2.0 and the latest Android 5.1 Lollipop update with the ability to handle the Android M beta.

Nexus 6 has a nearly bezel-free display, so the finger-stretching dimensions actually manage to be not too far off the size of the iPhone 6 Plus, which includes Apple's physical home button. The size of the phone is comparable, yet the screen size happens to be much bigger.

Of course, its bumped up cost isn't as budget-friendly at $650 full price - more than double the $300 starting price of the now discontinued Nexus 5. It's $249 through AT&T, but now $199 on-contract through Verizon. Just make sure you can properly hold this two-handed phablet before entering into a binding two-year commitment or opting for the very pricey no contract option.